My 2.5L Boxster is slow: 8.5 sec 0-60. Ideas?

[Carlton Bale]

I purchased my 99 Boxster new in 1998 and haven't had any major engine-related problems. However, recently, it just seemed to be really sluggish, especially compared to my Infiniti G35 Sedan. So I took a stop watch and a windshield-mounted G meter and measured 0-60 times. After about 6 tries, the best I could do was 8.5 seconds on either (estimating the speedometer delay). I know the 2.5L engine isn't exactly powerful, but I should be getting much faster 0-60 times. I figure there is probably a sensor problem, rather than a major mechanical problem. The car runs well otherwise. Any ideas what the cause may be?

I've heard of Gass Mass Flow Sensors causing low power. Is that a likely cause for me? What about the Oxygen Sensors? Thanks in advance for any help.

-Carlton

Edited August 7, 2005 by Carlton Bale

[J9000]

You need a new engine :) we are using 3.4 or 3.6 nowadays..

[deliriousga]

Several things can do it. Bad or low octane gasoline, MAF, O2 Sensors, vacuum leak, clogged air intake, clogged air filter, clogged exhaust or cats....

Do you have a K&N air filter or another type you oil? Over-oiling can cause the MAF to go bad.

[Carlton Bale]

Several things can do it.  Bad or low octane gasoline, MAF, O2 Sensors, vacuum leak, clogged air intake, clogged air filter, clogged exhaust or cats....

Do you have a K&N air filter or another type you oil?  Over-oiling can cause the MAF to go bad.

<{POST_SNAPBACK}>

I've always used 93 Octance gasoline, so I don't think that is it. The air filter was just changed a couple of weeks ago and I'm using the stock filter, so I don't think that is it.

Over on PPBB, I found out that the Oil / Air Separator (Closed Crankcase Ventilation) system is a likely cause. They apparently go bad and deposite large amounts of oil into the intake. I ordered a new separator and spark plugs. Still concerned about the MAF, but I'll wait to replace that.

Any idea on how to convert the Closed Crankcase Ventilation into a Positve Crankcase Ventilation system? I'd rather not have this issue again. . .

Edited August 9, 2005 by Carlton Bale

[Jinster]

93 Octane? In Aussie, the stock specification is 96 Octane or above. And so we all use 98 Octane since the next grade down is 95 here.

[valcax]

93 Octane? In Aussie, the stock specification is 96 Octane or above. And so we all use 98 Octane since the next grade down is 95 here.

<{POST_SNAPBACK}>

93 octane? are you sure? porsche recommends 98 octane and in case of emergency 95 minimum!!! :huh:

[ar38070]

Not to be US centric but when you speak of octane numbers make sure you are talking apples and apples, i.e. RON, MON or (RON+MON)/2, so as to avoid confusion.

[Carlton Bale]

Not to be US centric but when you speak of octane numbers make sure you are talking apples and apples, i.e. RON, MON or (RON+MON)/2, so as to avoid confusion.

<{POST_SNAPBACK}>

Sorry for the confusion. 93 Octane via the (RON+MON)/2 method.

[ar38070]

Are you getting any kind of OBDII faults?

Before going to the trouble or replacing the air/oil separator check to see if you are getting oil in the intake. Just take off the intake hose at the throttle body and have a look.

How many miles on the car?

[Carlton Bale]

Are you getting any kind of OBDII faults? 

Before going to the trouble or replacing the air/oil separator check to see if you are getting oil in the intake.  Just take off the intake hose at the throttle body and have a look.

How many miles on the car?

<{POST_SNAPBACK}>

No, there are no faults at all. I'm pretty sure I'm getting oil in the intake but I guess I should have confirmed it first. Another symptom, that I didn't think was related, is that going from high engine speed immediately to closed throttle causes the engine to stumble a little. As soon as the throttle is depressed again, lots of blue smoke out the exhaust. So far, it only happens under this scenario, but it will probably get worse. I'm hoping that a new crankcase filter, new plugs, and a cleaned intake will solve the problem.

The car has a little over 30,000 miles on it.

I plan on starting disassmebly this weekend. I'll post an update.

[ar38070]

That is your first mention of smoke. So definitely pull apart the intake and check for oil. If you find oil then your best bet is the air/oil separator.

[Carlton Bale]

Yeah, I didn't even think of the smoke being related until I saw mention of it on PPBB. I've only experienced "the smoke screen" about three times. However, I'm now guessing that oil has been passing in smaller quantities for quite some time.

[Carlton Bale]

Don't you hate it when people never report back what the problem was??

The occasional white smoke was from oil in the intake. I thought it was a bad air/oil separator, but it turned out to be the oil pan was over-filled with oil by "a few" quarts. Not sure exactly how many, but probably 3 or 4. This was the cause of oil in the intake.

I still had somewhat of a low-power issue after fixing that though. It was mostly hesitations above 4000 RPM. The O2 sensor finally tripped a fault and the hesitation and low-power issue was resolved.

So, don't let anyone overfill your oil pan and never trust the O2 sensor, at least that is what worked for me.

[Stefan]

If you have have been burning oil for a while there is a reasonable chance that your plugs have been fouled. I would remove one and check it.

I would also definitely check the air filter. You can always take it out, shake it off and put it back in if you don't have a replacement.

[Carlton Bale]

If you have have been burning oil for a while there is a reasonable chance that your plugs have been fouled. I would remove one and check it.

I would also definitely check the air filter. You can always take it out, shake it off and put it back in if you don't have a replacement.

Oh yeah, I forgot to mention, I did replace the plugs. I thought that would solve the hesitation at high engine speeds, but it did not. The O2 sensor was the major culprit.

Thanks for everyones help!

[El Patrick]

If you have have been burning oil for a while there is a reasonable chance that your plugs have been fouled. I would remove one and check it.

I would also definitely check the air filter. You can always take it out, shake it off and put it back in if you don't have a replacement.

Oh yeah, I forgot to mention, I did replace the plugs. I thought that would solve the hesitation at high engine speeds, but it did not. The O2 sensor was the major culprit.

Thanks for everyones help!

How come the bad O2 sensor didn't show a check engine light right when it went bad? Was the loss of power from this whole episode drastic? I'm just wondering because my father is thinking of purchasing a 2005 987 Boxster but when we test drove it we were surprised at how slow it was. We're wondering if there was a problem. It sure didn't feel like a 240hp car. I used to have a 1997 BMW M3 and that car felt way faster than this Boxster and that concerned me.

And also, how can I tell if the car is overfilled with oil? We're very new to the whole Boxster thing and I noticed this 2005 Boxster doesn't have a dip stick by the oil cap like a 2001 Boxster S did that I looked at...

Thanks for the help.

[Westcoaster]

If you have have been burning oil for a while there is a reasonable chance that your plugs have been fouled. I would remove one and check it.

I would also definitely check the air filter. You can always take it out, shake it off and put it back in if you don't have a replacement.

Oh yeah, I forgot to mention, I did replace the plugs. I thought that would solve the hesitation at high engine speeds, but it did not. The O2 sensor was the major culprit.

Thanks for everyones help!

How come the bad O2 sensor didn't show a check engine light right when it went bad? Was the loss of power from this whole episode drastic? I'm just wondering because my father is thinking of purchasing a 2005 987 Boxster but when we test drove it we were surprised at how slow it was. We're wondering if there was a problem. It sure didn't feel like a 240hp car. I used to have a 1997 BMW M3 and that car felt way faster than this Boxster and that concerned me.

And also, how can I tell if the car is overfilled with oil? We're very new to the whole Boxster thing and I noticed this 2005 Boxster doesn't have a dip stick by the oil cap like a 2001 Boxster S did that I looked at...

Thanks for the help.

To check the oil level, insert the key, turn the ignition to on (but do not start), the OBC will display the oil level as a series of bars in the window of the instrument cluster. There should be one unshaded bar at the top of the graphic.

If the engine has recently been run this process can take a number of minutes, if the car has sat for about 30 minutes or more the process takes only a few seconds. Of course the car should be level for this task.

Interesting comment about the 2005 being 'slow', it should be on par with the 'S' you drove.

Edited October 27, 2008 by Westcoaster

[El Patrick]

If you have have been burning oil for a while there is a reasonable chance that your plugs have been fouled. I would remove one and check it.

I would also definitely check the air filter. You can always take it out, shake it off and put it back in if you don't have a replacement.

Oh yeah, I forgot to mention, I did replace the plugs. I thought that would solve the hesitation at high engine speeds, but it did not. The O2 sensor was the major culprit.

Thanks for everyones help!

How come the bad O2 sensor didn't show a check engine light right when it went bad? Was the loss of power from this whole episode drastic? I'm just wondering because my father is thinking of purchasing a 2005 987 Boxster but when we test drove it we were surprised at how slow it was. We're wondering if there was a problem. It sure didn't feel like a 240hp car. I used to have a 1997 BMW M3 and that car felt way faster than this Boxster and that concerned me.

And also, how can I tell if the car is overfilled with oil? We're very new to the whole Boxster thing and I noticed this 2005 Boxster doesn't have a dip stick by the oil cap like a 2001 Boxster S did that I looked at...

Thanks for the help.

To check the oil level, insert the key, turn the ignition to on (but do not start), the OBC will display the oil level as a series of bars in the window of the instrument cluster. There should be one unshaded bar at the top of the graphic.

If the engine has recently been run this process can take a number of minutes, if the car has sat for about 30 minutes or more the process takes only a few seconds. Of course the car should be level for this task.

Interesting comment about the 2005 being 'slow', it should be on par with the 'S' you drove.

That's what I thought so I'm wondering if there's a problem with the car. The S I drove definitely felt faster. What else could be a cause for loss of power? Also, I noticed the engine fan was very loud and it kept running for a pretty long time. It sounded like a home air conditioner haha. Is that normal? Also, when engaging the clutch when taking off in first gear, the car shudders a little bit. I didn't notice any clutch slippage as I drove the car pretty hard, but could the shudder mean the clutch needs replacing?

[Christa]

93 octane are very low for best performance ,i use 100 octane BP ultimate the car works great with 100 and go slow with 95 or 98 . do you know if your injactors need cleaning in 30000miles means about 60.000 km?

[renzop]

93 octane are very low for best performance ,i use 100 octane BP ultimate the car works great with 100 and go slow with 95 or 98 . do you know if your injactors need cleaning in 30000miles means about 60.000 km?

Christa,

In the US we measure octane differently and the numbers are lower. Premium fuel is 91-93 octane (porsche recommends 91 or above). A mid grade is 89 and regular grade is 87. Those numbers are different than what you are used to seeing, just like 60K miles is about 100K KM.

[juniinc]

sounds like U need to check the plug gap.